Hogaak, Arisen Necropolis + Infested Thrinax + Phantom Train

Hogaak, Arisen Necropolis

Infested Thrinax

Phantom Train

How it works

1. Cast Infested Thrinax by paying 3.
2. When Infested Thrinax enters the battlefield, it triggers, causing you to create a number of 1/1 Saproling creature tokens when a nontoken creature you control dies.
3. Activate Phantom Train by sacrificing Hogaak.
4. When Hogaak dies, Infested Thrinax triggers, creating eight 1/1 Saproling creature tokens.
5. Resolve the Phantom Train ability
6. Cast Hogaak from your graveyard by tapping seven Saprolings.
7. Repeat from step 3.

This clever loop relies on Hogaak, Arisen Necropolis being able to be cast directly from your graveyard without spending mana, instead utilizing its delve and convoke abilities. When you activate Phantom Train to sacrifice Hogaak, Infested Thrinax’s triggered ability sees Hogaak's massive eight power and floods your board with eight Saproling tokens. You can then tap seven of those newly minted Saprolings to pay for Hogaak's convoke cost, casting it right back from the graveyard so Phantom Train has another sacrifice target to grow with a +1/+1 counter and repeat the entire cycle.